沤肥浸渍液对黄瓜霜霉病的抑制作用及其机理

本文报道在温室条件下堆沤半年以上的各种家畜粪肥浸渍液对黄瓜霜霉病的防治效果及其机理初步研究,经3次重复试验得出:马粪沤肥浸渍液对黄瓜霜霉病的平均抑制率为67.33％,牛粪沤肥浸渍液对黄瓜霜霉病的平均抑制率为66.10％,羊粪、猪粪沤肥浸渍液也分别对黄瓜霜霉病有一定的抑制作用,但低于马粪、牛粪。马粪、羊粪沤肥浸渍液经100℃高温2h灭活后对黄瓜霜霉病仍有抑制作用,且抑制效果高于相应非灭活的沤肥浸渍液。经沤肥浸渍液处理的植株,叶绿素含量和过氧化氢酶活性均比对照明显增高,致使黄瓜抗病性增强。

THE INHIBITORY EFFECTS OF COMPOST EXTRACTS ON CUCUMBER DOWNY MILDEW AND THE POSSIBLE MECHANISM

The authors studied the inhibitory effects of 4 compost extracts from dungs of horses, cows, sheeps, and pigs, on cucumber downy mildew (Pseudoperonospora cubensis (Berk, et Curt. ) Rost) under greenhouse condition and the possible mechanism. The compost extracts of horse and cow dungs showed effective control of cucumber downy mildew. The relative efficiencies were correspondingly 67. 33% and 66. 1% as compared with control. The compost extracts of sheep and pig dungs acted less effective (46. 5% and 57. 3% correspondingly) and unstable. The compost extracts could significantly increase the contents of chlorophyll and peroxidase activity. All the cucumber plants treated with 4 compost extracts contained more chlorophyll(19. 1% -24. 2%) than that in control cucumber (18. 19%). In compost extracts treated cucumber plants the peroxidase activity was also higher than that in control cucumber. In cucumber plants treated with compost extracts of horse, pig, cow or sheep dungs the peroxidase activity were 176. 12 - 194. 48 mg-H2 O2 g-1min-1, while in control plants the activity value was only 149. 6 mg-H2 O2 g-1min-1, The compost extracts may contain some biotic and abiotic factors which may varys under different conditions. After sterilizing compost extracts the relative efficiency increased up in 21. 7% in horse dungs and 47. 65% in sheep dungs, but significantly decreased in cow and pig dungs.